Surgical operations often involve the cutting of a patient's tissue. Usually, the tissue is cut with a scalpel, a sharp edged cutting instrument. However, the cutting of a patient's tissue is also usually accompanied by an undesired flow of blood from small blood vessels within the tissue. Reducing, or eliminating this blood flow is advantageous to the patient by reducing blood loss and to the surgeon by removing or reducing an obstruction to the surgeon's view of the incised tissue.
Scalpels making use of lasers for heat sources can be used to heat and irradiate the incised tissue. Light of an appropriate wavelength is absorbed by the tissue, and the optical energy is converted to thermal energy to cauterize the tissue. Cutting instruments of this type are described in U.S. Pat. Nos. 6,383,179; 5,571,098; 5,366,456; and 4,627,435. These devices can use the laser to incise the tissue as well as cauterize, or use an optically transparent material for the cutting instrument coupled with a bundle of optical fibers for directing the laser to the area of interest.
Another method of providing cauterizing heat with a scalpel is the use of ultrasonics. U.S. Pat. No. 5,324,299 describes such a device wherein the scalpel blade is vibrated at a rate around 55,000 cycles per second. The vibration generates ultrasound waves for heating the tissue, however, there is only limited cauterizing ability.
Control of blood loss can be achieved by cauterizing the small blood vessels in the tissue at the time the tissue is cut. Cauterization of the blood vessels is achieved by applying heat at the vessels. It is advantageous to apply the heat at the time the tissue is cut and at the tissue without exposing the tissue to radiation.